wood bucket

bucket = {}
bucket.liquids = {}

minetest.register_craft({
    output = 'alternative:wood_bucket 1',
    recipe = {
        {'default:wood', '', 'default:wood'},
        {'', 'default:wood', ''},
    }
})

function bucket.register_liquid(source, flowing, itemname, inventory_image)
    bucket.liquids[source] = {
        source = source,
        flowing = flowing,
        itemname = itemname,
    }
    bucket.liquids[flowing] = bucket.liquids[source]

    if itemname ~= nil then
        minetest.register_craftitem(itemname, {
            inventory_image = inventory_image,
            stack_max = 1,
            liquids_pointable = true,
            on_use = function(itemstack, user, pointed_thing)
                -- Must be pointing to node
                if pointed_thing.type ~= "node" then
                    return
                end
                -- Check if pointing to a liquid
                n = minetest.env:get_node(pointed_thing.under)
                if bucket.liquids[n.name] == nil then
                    -- Not a liquid
                    minetest.env:add_node(pointed_thing.above, {name=water_source})
                elseif n.name ~= source then
                    -- It's a liquid
                    minetest.env:add_node(pointed_thing.under, {name=water_source})
                end
                return {name="alternative:wood_bucket"}
            end
        })
    end
end

minetest.register_craftitem("alternative:wood_bucket", {
    description = "Wood bucket",
    inventory_image = "alternative_wood_bucket.png",
    stack_max = 1,
    liquids_pointable = true,
    on_use = function(itemstack, user, pointed_thing)
        -- Must be pointing to node
        if pointed_thing.type ~= "node" then
            return
        end
        -- Check if pointing to a liquid source
        n = minetest.env:get_node(pointed_thing.under)
        liquiddef = bucket.liquids[n.name]
        if liquiddef ~= nil and liquiddef.source == n.name and liquiddef.itemname ~= nil then
            minetest.env:add_node(pointed_thing.under, {name="air"})
            return {name=liquiddef.itemname}
        end
    end,
})

bucket.register_liquid(
    "default:water_source",
    "default:water_flowing",
    "alternative:wood_bucket_water",
    "alternative_wood_bucket_water.png"
)